Cobalt and Cobalt Compounds

Overview

In November 2022, EPA released the Draft IRIS Assessment Plan (IAP) and Protocol for Assessing Cancer Risk from Inhalation Exposure to Cobalt and Cobalt Compounds for public review and comment. An IRIS Assessment Plan (IAP) communicates to the public the plan for assessing each individual chemical and includes summary information on the IRIS Program’s scoping and initial problem formulation; objectives and specific aims for the assessment; the PECO (Populations, Exposures, Comparators, and Outcomes) criteria that outlines the evidence considered most pertinent to the assessment; and identification of key areas of scientific complexity. The PECO provides the framework for developing literature search strategies and inclusion/exclusion criteria, particularly with respect to evidence stream (i.e., human, animal, mechanistic), exposure and outcome measures. EPA also released the IRIS assessment protocol for cobalt, which describes the methodology for how the assessment will be conducted, including dose-response methods.

Background

Cobalt is a metallic element that is naturally occurring as several different substances and oxidation states, often in association with nickel, silver, lead, copper, and iron ores. Cobalt compounds represent a large group of substances and are used in a variety of industrial applications including as a colorant for glass, ceramics, and paint; as driers for inks and paints; as catalysts; and in feed supplements and batteries. Cobalt is also used in alloys or composites. The cancer assessment of water-soluble and water-insoluble cobalt compounds is focused on inhalation exposure from emissions to air during industrial processes and those cobalt forms most pertinent to implementing the Clean Air Act (CAA).

History/Chronology

Date	Description
Nov 2022	EPA released the draft IRIS Assessment Plan and Protocol for Assessing Cancer Risk from Inhalation Exposure to Cobalt and Cobalt Compounds for a 30-day public comment and review period. [Federal Register Notice Nov 14, 2022]

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

• IRIS Assessment Plan and Protocol for Assessing Cancer Risk from Inhalation Exposure to Cobalt and Cobalt Compounds (PDF)  (88  pp, 2.2 MB, about PDF)
• IRIS Public Science Meeting on Cobalt and Cobalt Compounds (Jan 2023)

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Federal Register Notices

• FR Notice: Dec 2, 2022
• FR Notice: Nov 14, 2022

Docket

Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2022-0833